Joint and connecter



May 24, 1938.

T. c. GREEN 2,118,672

JOINT AND CONNECTER Filed Sept. 14, 1956 INVENTOR THOMAS C. GREEN Q M ATTORNEY Patented May 24, 1938 UNITED STATES JOINT AND CONNECTER Thomas C. Green, United States Marine Corps Application September 14, 1936, Serial No. 100,689

3 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3'70 0. G. 757) My invention relates to an electrically continuous, substantially fluid impervious joint and to a connecter for connecting together an electrically conductive element provided with an opening and an electrically conductive casing element and for insuring electrical continuity and continuity of passage therebetween.

In order to effectively shield extraneous apparatus against electro-magnetic and electro-static disturbances caused by ignition circuits of internal combustion engines, it is essential that the circuit be completely enveloped by a metallic surface; that the enveloping metallic surface be grounded at its ends and at suitable intervals therebetween; and that the enveloping metallic surface be electrically continuous throughout its length. Failure of the enveloping metallic surface to properly and effectively shield against the deleterious disturbances generated by the ignition circuits is caused principally by lack of electrical continuity along the enveloping metallic surface, or an increase in resistance of the enveloping metallic surface over that at which optimum shielding is obtained. This lack of electrical continuity or increase of resistance.takes place at the connecters and joints. forming a part of the enveloping metallic surface. As long as the contacting surfaces of the connecters and joints are in intimate metallic contact and remain free from dirt, oil, gasoline, or other extraneous matter, the enveloping metallic surface will effectively shield. If, however, the contacting surfaces of the connecters and joints are not in intimate metallic contact, or do not remain free from extraneous matter, there will be a lack of electrical continuity or an increase of resistance through the connecters and joints with attendant interruption or mal-functioning in the shielding properties of the enveloping metallic surface.

Shielding failure in aircraft shielding assemblies is commonly caused by the through connecter which connects a junction box adjacent the opening therein with a shielding conduit or by the joint which this connecter makes with the wall or partition of the junction box adjacent the opening or outlet therein, since both connecter and joint fail to perform their primary function of providing electrical continuity between the junction box and shielding conduit. In the prior art shielding assemblies the joint at the opening or outlet in the junction box is formed by causing the sides of the junction box to contact, respectively, with a flange at one end of an externally threaded connecter body and with a face of a nut in threaded engagement with said body. Sole reliance for electrical continuity at this'joint is placed upon the contact made by the flange and nut with the sides of the junction box adjacent the opening therein. As it is general practice to paint junction boxes before installing the through connecter in the outlet hole thereof, electrical contact between the sides of the junction box and the through connecter is dependent upon some part of the connecter rubbing away sufficient paint during installation to make contact with the metal beneath. During installation the nut is usually the connecter part which is rotated in order to secure the connecter tightly in place and consequently when fortuitous electrical contact occurs between the connecter and the sides of the junction box it is usually between a face of the nut and the outside wall of the junction box, where this mutual contact is most subject to destruction by oil or corrosion due to moisture.

With the foregoing preliminary discussion in view, it is an object of my invention to provide a joint wherein the juncture between the joint parts is sealed against the exterior whereby elec trical continuity through the joint is insured.

It is another object of my invention to provide an electrically continuous joint wherein the juncture between the joint parts is maintained by direct and intimate metallic contact, the said juncture being sealed against the exterior to thus preserve unaltered the resistance through the joint.

it is another and further object of my invention to provide a connecter for connecting an electrically conductive casing element to an electrically conductive element having an opening, and for insuring electrical continuity and continuity of passage therebetween.

it is another and still further object of my invention to provide a connecter for connecting an electrically conductive casing element to an electrically conductive element having an opening, and for insuring electrical continuity and continuity of passage therebetween, wherein 'the juncture between the connecter parts and the juncture between one end of the connecter and the electrically conductive element adjacent the opening therein are maintained by direct and intimate metallic contact, the said junctures being sealed against the exterior to thus preserve unaltered the resistance therethrough and to insure electrical continuity from one electrically conductive element to the other.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following description when considered in connection with the accompanying drawing wherein:

Figure 1 is an assembled view in section of my connecter and the joint which one end of the connecter makes with a wall adjacent an opening therein;

Figures 2 and 3 are, respectively, a view in section and a view in end elevation of the female connecter part or member; and

Figures 4 and 5 are, respectively, a view in end elevation and a view in section of the nut adapted for threaded engagement with the female connecter part.

My invention seeks to provide a connecter and a joint between one end thereof and an electrically conductive element provided with an opening which are not only electrically continuous but whose resistance is preserved substantially unaltered. To accomplish the foregoing I maintain a direct and intimate metallic contact between the male and female connecter parts by causing a wedging action between their contacting surfaces through the medium of a suitable coupling means, the contact or juncture between the connecter parts occurring within the confines of a compressible fluid impervious means to thus effectively seal the juncture against the connecter exterior. The joint is formed by providing the female connecter part at one end thereof with a plurality of projections which are forced into contact with the electrically conductive element adjacent the opening therein, the area of contact therebetween being sealed against the joint exterior.

The joint and connecter of my invention are intended primarily for use with the shielding of aircraft ignition circuits and are so described in their specific application hereinafter. It is to be emphasized, however, that the joint and connecter of my invention are not restricted to the aforementioned use but may be used wherever and whenever an electrically continuous joint and connecter are desired.

Turning now to the drawing there is shown in Figure l in assembled relation a connecter identified in general by the numeral I for connecting together the shielding conduit 2 and apertured wall 3 of a junction box and for permitting the passage of the ignition cable 4 from the conduit into the junction box, the said connecter including a female connecter part 5, a male connecter part 6, a deformable and compressible gasket 1 which serves as a fluid impervious sealing means and is interposed between the connecter parts and a coupling 8 for maintaining a direct and intimate metallic contact between the connecter parts and for causing the connecter parts to compress the gasket whereby to seal the surfaces of contact between the connecter parts against the connecter exterior. i

The female and male connecter parts or bodies 5 and 6 are apertured at 9 and I 0, respectively, to permit the passage of the ignition cable 4 from the shielding conduit 2 into the junction box. In addition one end of the female connecter part 5 is provided with a conical recessed surface H with which a corresponding conical surface I2 of the male connecter part 6 is adapted to contact, to thereby insure electrical continuity through the connecter. While the contactingsurfaces of the male and female connecter parts are shown as conical in shape, I do not desire to be restricted thereto since other inclined contact surfaces may be employed within the purview of my invention and will readily suggest themselves to those skilled in the art, hemispherical surfaces and pyramidal surfaces being illustrative but not restrictive of such other inclined surfaces.

The female and male connecter parts 5 and 6 are furthermore provided with bearing faces l3 and M, respectively, extending outwardly of the connecter from adjacent the outermost edges of the conical or inclined surfaces II and I2, these bearing faces being adapted to abut against the sides of the deformable, fluid impervious gasket l interposed therebetween to compress the same and thereby seal the surfaces of contact II and i2 between the connecter parts or bodies 5 and 6 against the connecter exterior. The gasket 1 is preferably, although not necessarily, annular in shape and is placed about and supported by the cylindrical portion l5 of the male connecter part 6. This gasket which serves as a sealing means may be fabricated from synthetic rubber or any other suitable material so long as the material chosen is fluid impervious, will withstand the weather and be reasonably resistant to fluids such as, for example, gasoline, oil, and Water.

In order to insure a direct and intimate metallic contact between the contacting surfaces II and I2 of the connecter parts and a compression of the gasket 1, the male and female connecter parts have been provided with a flange l6 and screw threads II, respectively, which are adapted to engage a complemental flange l6 and internal screw threads ll of a coupling sleeve or nut I. Portions N3 of the coupling sleeve or nut 8 are hexagonally or otherwise shaped to permit the use of a wrench for tightening purposes. The coupling sleeve or nut 8 in addition to holding the contact surfaces H and I2 of the connecter parts in intimate and direct metallic contact and of the gasket 1,

connecter.

The male connecter part 6 is recessed or rabbeted at l9 to provide inner and outer walls 20 and 2!, respectively, between which the shielding conduit 2 is received. Since in this embodiment of can be readily soldered, the male connecter part is attached to its shielding conduit 2 of similar material by sweating the outer wall 2| with solder to the outside of the conduit. The inner wall 20 of the male connecter part 6 in this case serves to support the inside of the shielding conduit 2 and to prevent sharp edges thereof from causing damage to the ignition cable 4.

Where, however, the connecter parts are made of an aluminum alloy or metal which cannot be conveniently soldered to a shielding conduit of similar material, I may employ an alternate mode of connection which consists in swaging the outer sleeve 2| inwardly around the shielding engagement between the male connecter part and the shielding conduit.

The threaded body portion of the female connecter part 5 is provided at another end thereof with a plurality of circumferentially spaced projections or splines 22 and a flange 23, the said projections being forced into the wall 3 of the junction box adjacent the opening therein and being in direct and intimate electrical contact therewith. A fluid impervious gasket 24 is interposed between the flange 23 wall 3 of the junction box and a second gasket 25 placed adjacent the opening in the wall 3 and on the other side thereof, these gaskets being and one side of the.

compressed and held in fluid impervious engagement with the sides of the wall 3 by means of a nut 26. Both gaskets are fabricated in a manner similar to that of the gasket 1. The nut 26 has a portion of the inner face cut away at 21 to provide space for the projections or splines and/or the metal they displace, while permitting a tight fit between the inner face of the nut and the fluid impervious gasket 25 and the use of the connecter regardless of the thickness of the wall or partition 3 through which it passes. A tight flt between the wall 3 of the junction box, on the one hand, and the gaskets 24 and 25, the flange 23 and the nut 26, on the other hand, is essential in order to effectively seal the area of contact between the projections 22 and the junction box wall 3 against the exterior and hence against the,

introduction of any extraneous'matter such as, for example, oil and water. It is to be emphasized, however, that the washers or gaskets 24 and 25 need not be employed since a joint which is substantially and effectively sealed against the exterior may be obtained by causing the inner faces of the flange 23 and the nut 26 to intimately contact the faces of the wall 3.

In use the female connecter part is placed through the opening in the wall 3 of the junction box and the nut 26 threaded thereon and tightened with or without the interpositioning of gaskets 24 and 25. The tightening of the nut causes the projection 22 to cut into the wall 3 of the junction box adjacent the opening therein and thus to provide a direct and intimate electrical contact therewith. The tightening of the nut 26 serves also to provide a substantially fluid impervious juncture between the wall 3, on the one hand, and the flange 23 and nut 26, on the other hand, to thereby seal the area of contact between the wall 3 and the projections 22 against the exterior and thereby insure electrical continuity at this joint. The nut 8 is now assembled over the male connecter part 6 and the fluid impervious gasket I placed about the cylindrical portion l5 of the male connecter part. The female connecter part 5 is then brought into place and the parts secured together by tightening the coupling sleeve 8. As the sleeve or nut 8 is tightened the conical projection on the male connecting part is wedged into the corresponding conical recess of the female connecting part thus providing direct electrical continuity through the connecter. Simultaneously with the tightening of the nut or sleeve 8 the sides of the gasket 1 are compressed betwegi the bearing faces l3 and ll of the connecter parts thus sealing within its confines the surfaces of contact II and I2 of the connecter parts against the introduction of extraneous materials such as gasoline, oil and This invention may be manufactured and used v by or for the Government of the United States of America for governmental purposes without payment of royalties thereon-or therefor.

I claim:

1. Means for connecting an electrically conductive casing element' to an electrically con- .ductive element provided with an opening and for insuring electrical continuity and continuity of passage therebetween, comprising in combination an apertured, electrically conductive body provided with a plurality of spaced projections at one end thereof and a bearing face and inclined, recessed, contact surface at the other end thereof, means for forcing the projections into electrical contact with the electrically conductive element adjacent the opening therein and for sealing the area of contact therebetween against the connecter exterior, a second apertured electrically conductive body adapted for connection to said casing element and having a contact surface in electrical contact with that of said first mentioned body and a bearing face, deformable means interposed between the bearing faces of said bodies and adapted to be engaged thereby for sealing the area of contact at the surfaces of said bodies against the connecter exterior, and means for holding said bodies in wedging engagement at their surfaces of contact and for causing the bearing faces to abut against the deformable means interposed therebetween.

2. An electrically continuous shielding assembly comprising in combination an electrically conductive casing element, an electrically conductive element provided with an opening and means for connecting said elements together and for insuring electrical continuity and continuity of passage therebetween, said means including an apertured, electrically conductive body provided with projecting means at one end thereof and a contact surface at the other end thereof, means for forcing the projecting means into electrical contact with the electrically conductive element adjacent the opening therein and for sealing the area of contact therebetween against the connecter exterior, a second apertured electrically conductive body electrically continuous with said casing element and having a contact surface in contact with that of said first mentioned body, means for sealing the area of contact between said first and second mentioned bodies against the connecter exterior, and means for holding said first and second mentioned bodies in engagement.

3. Means for connecting an electrically conductive casing element to an electrically conductive element provided with an opening and for insuring electrical continuity and continuity of passage therebetween, comprising in combination an apertured, electrically conductive body provided with projecting means at one end thereof and a contact surface at the other end thereof, means for forcing the projecting means into electrical contact with the electrically conductive element adjacent the opening therein and for seal-= ing the area of contact therebetween against the connecter exterior, a second apertured electrically conductive body adapted for connection to said casing element and having a contact surface in contact with that of said first mentioned body, means for sealing the area of contact between said first and second mentioned bodies against the connecter exterior, and means for holding said first and second mentioned bodies in engagement.

. THOMAS C. GREEN. 

